Not applicable.
Not applicable.
The invention generally relates to apparatus for monitoring medical patients; and more particularly to such apparatus which include an audible alarm.
Medical patients, especially those in an intensive care facility, often are connected to equipment which continuously monitor specific physiological activity that is relevant to the particular malady of which the patient suffers. For example, a patient with heart disease may be connected to an electrocardiograph and a blood pressure monitor. Such monitors have sensors attached to the patient, analyze the signals from the sensors, and display the physiological information to the medical personnel. In the case of an electrocardiograph, the cardiac waveform is displayed on a graphical display device or printed out on paper. Blood pressure monitors will have numerical displays indicating the systolic pressure, diastolic pressure and possibly other parameters, such as mean arterial pressure.
Rather than requiring that medical personnel constantly monitor the display of physiological information, audible alarms are often provided in the event that the physiological parameters exceed reasonable limits for a particular patient. For example, the systolic and diastolic blood pressures can be compared to threshold values for each parameter. When a given threshold is exceeded, an audible alarm is activated in the monitor to alert the medical personnel. Indicator lights also are used to indicate an abnormal condition. Alarms also are provided to indicate a malfunction of the monitoring equipment, such as a low battery charge for portable equipment or the sensor signal being lost as occurs when the sensor detaches from the patient.
Such audible alarms typically produce a relatively loud piercing sound so as to be heard over other sounds in the area of monitoring. As a consequence, the audible alarms may agitate the patient which in certain medical conditions is very undesirable. Furthermore, the patient may be agitated unnecessarily when the alarm indicates a relatively non-critical event, such as a loose sensor lead.
Furthermore, the use of an audible alarm such as produced by a piezoelectric annunciator or buzzer does not provide an indication of the exact condition for which the alarm is being sounded. The same annunciator may be used to indicate a number of events, such as the physiological parameters going out of bounds, a low battery, or a loose electrical sensor. However, the medical personnel cannot determine the nature of the alarm condition from the sound and thus, cannot determine whether an immediate response is required or whether the alarm condition can be remotely deactivated, such as from a nurse""s station.
It has been proposed to provide a warning mechanism which produces a stored voice message indicating the nature of the alarm condition and even providing a message to soothe the patient to prevent agitation during this event. However, in order for medical equipment to be marketable worldwide, the alarm messages must be presented in the native language of the country in which the equipment will be used. If the medical personnel will not understand a message recorded in another language, then the alarm feature is useless. This leads to a requirement that the given medical monitor must be produced with a model for different languages and various dialects. This is especially unfeasible in the case of a relatively small nation with a unique language. Furthermore, different applications of a monitor in hospitals, clinics, or home settings may call for different message phrases for the same conditions. Different medical facilities using the same language also may refer to a given Medical event by different phrases.
Thus there is a need to be able to easily customize a patient monitor""s voice messaging system for the particular location at which it is being used.
A patient monitor has one or more audio messages stored in a memory. When the patient monitor detects an occurrence of a predefined condition, such as an usual physiological characteristic of the patient, an audio message associated with that condition is played back through a loudspeaker. To enable the patient monitor to be used throughout the world, the end user is able to replace each prerecorded audio message. Thus the end user is able to store voice messages in the native language and dialect spoken where the monitor is used.
Specifically, the patient monitor incorporating the audio messaging system has circuitry which senses a physiological characteristic of a medical patient and produces a control signal indicating an occurrence of a predefined event. An audio input device, such as a microphone for example, and a loudspeaker are provided. An audio processor has an input connected to the audio input device and has an output connected to the loudspeaker. A control input is coupled to the circuitry for receiving the control signal. A memory is included to store an audio message related to the event. The audio processor has a first operating mode in which a signal produced by the user is received at the input and stored in the memory as the audio message. In a second operating mode of the audio processor responds to receipt of the control signal by retrieving the stored audio message from the memory and generating a signal at the output.